Guitar



H. WILLNER June 21, 1949.

GUITAR Filed Feb. 16, 1948 I INVENTOR} HUGO WI LL NER .ATT'ORNEY Patented June 21, 1949 GUITAR Hugo Willner, Vancouver, British Columbia, Canada Application February 16, 1948, Serial No. 8,543

3 Claims.

My invention relates to improvements in guitars.

The object of the present invention is to provide means for reinforcing or trussing that portion of the sound board of a guitar or other similar instrument, so that the tension of the strings does not deflect or deform the said sound board. For instance, the surface of the sound board of the guitar shown in this embodiment of the invention, is a plane and where in guitars as normally made the strings are anchored to an anchor bridge and bear down upon an auxiliary bridge, a torque is developed at the anchor bridge and the board develops a slight concave depression between the anchor bridge and the sound hole of said sound board, the distortion thus created in said sound board efiects the tonal characteristics of the instrument, whereas where the sound board is trussed by adjustable means as shown in the subjoined specification, the distortion can be reduced or entirely avoided, with corresponding tonal changes to the instrument as a whole.

Referring to the drawings:

Fig. 1 is a transverse sectional view of a guitar looking up and showing the invention.

Fig. 2 is an enlarged sectional view of the invention taken on the line 2-4 of Figure 1.

In the drawings lik characters of reference indicate corresponding parts in each figure.

The numeral I indicates generally the body of a guitar having a back 2, side wall 3, a front wall or sound board 4 in which a sound hole 5 is provided in the usual manner. To the upper end of the body I a neck 1 is provided, which is fitted with appropriate devices (not shown) for the tensioning of strings 8.

The underside of the sound board l is provided with stiffening ribs In, H and I2, which are glued to the sound board and extending between the ribs H and I2 is a pair of spaced ribs or struts l4, also glued to the sound board. These struts converge from the rib l2 towards a tail block 16 which is fitted at the base of the body in contact with the wall 3, the back 2 and the sound board l. The rib H is thickened intermediate its length as at H and is fitted with a saddle l8, which latter extends below the sound board substantially the same distance as the auxiliary bridge 20 applied to the outer face of said sound board. The rib I0 is of a depth or thickness somewhat in excess of the usual anchor bridge 22 to which the strings 8 are attached in any appropriate manner. A pair of truss wires 24 are anchored to and extend through the rib l2 and extend convergingly under the rib II and in contact with the saddle l8, from the saddle they pass through the rib l0 and are fastened to screw pins 26. The screw pins 26 slidably, but non-rotatively, extend through the tail block it and are individually fitted with nuts 21, which serve to tension the truss wires 24 to substantially the same degree as the total tension of the strings 8 when properly tuned, or to such other tension as may be desired. If the tension on the truss wires is such as to balance th string load on the auxiliary bridge 20, the area of the sound board between the tail block l6 and the rib l2 will be normally lying in a single plane and will only be subject to such distortion as that set up by the vibration of the sound board responsive to the plucking of the strings.

The trussing of the sound board widens the scope of the instrument, enabling the tone to be hardened according to the tension of the wires 24. It is also possible to vary the tone as between the base and treble of the strings by tightening the left wire of the pair 24 to a different tension to that of the right wire. The tensioning is a simple matter and can be adjusted at any time, so that different tonal characteristics may be obtained between one piece of music and another played immediately after.

What I claim as my invention is:

1. In a stringed instrument of the guitar type, a truss comprising a transversely disposed strut member extending substantially below the sound board and substantially parallel to the string supporting bridge of the instrument, said sound board having a transverse rib adjacent the neck end of the instrument and a second rib adjacent the opposite end of said instrument, a. pair of tensional members extending in spaced relation between said ribs, said strut member being urged by said tensional members to support the sound board and its superposed string supporting bridge.

2. In a stringed instrument of the guitar type, a truss comprising a transversely disposed strut member extending substantially below the sound board and substantially parallel to the string supporting bridge of the instrument, said sound board having a transverse rib adjacent the neck end of the instrument and a second rib adjacent the opposite end of said instrument, a pair of tensional members extending in spaced relation between said ribs, each of said tensional members being anchored to one of the ribs and having sliding engagement with the other of said ribs, said tensional members serving to apply an upward thrust on the strut member, and means accessible from without the instrument for adjusting the tension of the tensional members.

3. In a stringed instrument of the guitar type, a. truss comprising a transversely disposed strut member extending substantially below the sound board and substantially parallel to the string supporting bridge of the instrument, said sound board having a transverse rib adjacent the neck end of the instrument and a second rib adjacent the opposite end of said instrument, a pair of ten-sional members extending in spaced relation between said ribs, each of said tensional members being anchored to one of the ribs and having sliding engagement with the other ofsaid ribs, said tensional members serving to apply an upward thrust on the strut member, said ten- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 476,907 Tibbits June 14, 1892 1,128,217 Bohanann Feb. 9, 1915 1,214,075 Rice Jan. 30, 1917 

